Problem: The arithmetic sequence $(a_i)$ is defined by the formula: $a_i = -1 - 4(i - 1)$ What is $a_{7}$, the seventh term in the sequence?
Solution: From the given formula, we can see that the first term of the sequence is $-1$ and the common difference is $-4$ To find $a_{7}$ , we can simply substitute $i = 7$ into the given formula. Therefore, the seventh term is equal to $a_{7} = -1 - 4 (7 - 1) = -25$.